A boat may be equipped with onboard washing facilities such as a washing machine, shower, bathtub and sinks. The boat may also be equipped with one or more air conditioners which produce condensate. Greywater discharges originate from such onboard sinks, showers, bathtubs, air conditioners (as condensate), and washing machines. Greywater is defined herein as “used water discharged from a boat, ship, RV, camper or the like, other than sewage or septage.”
Greywater has typically been collected in a sump equipped with a float switch to control (turn on and off) a sump/bilge pump. The float switch may be housed within a strainer. The float switch is electrically connected to the sump/bilge pump. The float switch is typically mounted on the floor of the sump. The typical sump has a flat floor. The drain for the sump equipped with a float switch may be found in an endwall or sidewall. The float rises simultaneously with the rising greywater. The rising float on the float switch physically closes an electrical circuit activating the sump/bilge pump. The sump/bilge pump evacuates the greywater from the sump, pumping the greywater overboard or into a greywater holding tank. The float switch lowers simultaneously with the evacuating greywater. As the greywater level lowers to a point above the floor of the sump, the float switch physically opens the same electrical circuit deactivating the sump/bilge pump. This cycle repeats itself automatically.
Unfortunately, this system fails to evacuate all the greywater within the sump. The residual greywater stagnates within the sump causing biological growth with associated odors. Unlike home plumbing systems, boat plumbing systems typically have no drain trap; drain traps prevent odors from drains entering a home. Odors from the current systems permeate the boat cabin. The biological growth may interfere with normal operation of the current systems causing their failure. Thus, greywater enters the sump, but does not completely discharge. These failures may cause backups, gross contamination and odor throughout the boat. Components for the current systems also require regular time-consuming and expensive maintenance and repair, often causing unexpected delays at dock.
Accordingly, there has been a need for a novel improved marine greywater disposal system and method which is of simplified construction, reliable, self-sustaining with substantially little or no maintenance, repair, or replacement, and substantially effective at automatically discharging greywater when washing or using an air conditioner onboard. There is also a need for a novel marine greywater disposal system for minimizing onboard biological growth and odor from greywater sumps. The present invention fulfills these needs and provides other related advantages.